1. Field of the Invention
The present invention relates to an electrical apparatus whose switching time to switch over to its power saving mode can be set up, in particular, an image forming device whose power saving mode switching time can be set up.
2. Description of the Related Art
In printers marketed these days, it is common to see a control system that switches from a normal mode in which a printing process is executable to a power saving mode which consumes less power than the normal mode, when a time period in which the printing process has not been executed exceeds a prescribed switching time, which is set up separately.
A certain fixed value is normally setup as a default value as the time to switch over to the power saving mode in order to satisfy various electrical standards concerning power saving, such as Energy Star. For example, in case of a color printer that copes with paper of size such as A3 and A4 and has a printing speed of 10<PPM ≦20, where PPM is a unit of printing speed (number of sheets printed per minute), a certain fixed value less than or equal to 60 minutes is set up as a default. In such a case, the time to switch over to the power saving mode can be adjusted by a user to match the usage environment for the printer within a prescribed range.
However, it is difficult for a user to set up a proper power saving mode switching time in case of a network printer connected to a network, as its usage frequency varies dynamically due to differences in usage time bands or changes in the number of users.
In order to solve this problem, various proposals were made for automatically setting up the power saving mode switching time in accordance with the printing frequency in a certain period time in the past or the amount of communication per unit time on the network (e.g., Unexamined Publication No. JP-A-2000-141820).
However, as mentioned above, it is necessary to set up a certain fixed value as a default value of the power saving mode switching time in order to satisfy various electrical standards such as Energy Star for an electrical apparatus such as a printer.
Therefore, it presented a problem that the technologies such as the one disclosed by the above patent application publication, which automatically set up the power saving mode switching time, cannot be applied for an electrical apparatus such as a printer as the methods of satisfying various electrical standards such as Energy Star.